Pain: Ferguson maintains Rooney has been sidelined by the injury to his
left ankle suffered on Sunday

Wayne Rooney has been ruled out by Sir Alex Ferguson for up to three weeks, meaning the troubled Manchester United striker will miss England's Euro 2012 qualifier against Montenegro.

Ferguson maintained Rooney had been sidelined by the injury to his left ankle suffered in Sunday's draw at Bolton.

It means the forward will sit out the Barclays Premier League games against Sunderland and West Bromwich Albion, as well as the international at Wembley on October 12.

But with United facing a light schedule either side of the international break, after tonight's difficult Champions League clash with Valencia, it is an ideal opportunity for the 24-year-old to step out of the spotlight and address issues in his personal life.

Ferguson said: 'Wayne will be two to three weeks. In fairness, he's a strong lad and has recovered from injuries in the past.'

Pressed on the state of the ankle, he added: 'What do you want me to say? Do you want me to describe every ligament? Christ.'

Ferguson was also asked about Rooney's mental state as he battles problems on and off the pitch. He has not scored from open play for United since March, and faces allegations that he cheated on his wife Coleen.

Together again: Rio Ferdinand warms up ahead of the Valencia
clash, in which he is expected to partner Nemanja Vidic in defence for
the first time this season

The United boss said: 'Nobody likes to be injured, it's straightforward. He'd like to be out here training and playing with us.'

Paul Scholes has also stayed at home with Rooney and Ryan Giggs after it was revealed the veteran midfielder has suffered a minor calf injury that will rule him out for 10 days.

It deprives Ferguson of vital experience as United look to secure only their second away win over Spanish opposition.

A lot on his shoulders: Dimitar Berbatov (centre) will carry the goal-scoring burden for Manchester United in the absence of Rooney

He said: 'You don't want to lose your best players, that goes without saying,' said Ferguson. 'The problem is with one of those small injuries like Paul has got, when you are travelling and sitting on a plane, stiffness comes into it and doesn't make it any better.

'It was a big decision to leave him behind. Because it is only a little one, you are tempted to play him when it is not wise. He should be ready in 10 days.'